• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Neumann KH 150 Monitor Review

Rate this studio monitor

  • 1. Poor (headless panther)

    Votes: 0 0.0%
  • 2. Not terrible (postman panther)

    Votes: 3 0.6%
  • 3. Fine (happy panther)

    Votes: 42 8.4%
  • 4. Great (golfing panther)

    Votes: 457 91.0%

  • Total voters
    502

HQY

Active Member
Joined
Jan 16, 2023
Messages
117
Likes
145
Location
Canada
I received one of the two ordered KH150. In use I noticed it becomes really hot at the back. That was not what I expected from class D amps. Is this normal? Do others have the same experience?
my 120iis are hot, same hot both of them. I did not expect them this hot but they work fine.
 

HarmonicTHD

Major Contributor
Forum Donor
Joined
Mar 18, 2022
Messages
3,326
Likes
4,803
I received one of the two ordered KH150. In use I noticed it becomes really hot at the back. That was not what I expected from class D amps. Is this normal? Do others have the same experience?
Also Class D Amps are not 100% efficient and have to put the heat somewhere. But much smaller (heatsinks) required as compared to similar powerful other concepts. So don’t worry.
 

boxerfan88

Senior Member
Joined
Oct 23, 2018
Messages
318
Likes
366
Did they shift to class D for the newer models?

I must have missed that info.
 

Filio45

Active Member
Joined
Feb 19, 2019
Messages
162
Likes
74
So they don't just run warm but 'hot'.

The SOS review of the KH 150 said that they used 'a patent-pending amp tech that combines superior audio performance with the energy efficiency of class D. The amp topography incorporates some novel techniques that take driver impedance into account with the feedback strategy..."

Neumann state 15w idle for the KH150, which is closer to what you would expect with class AB. In comparison, many 'regular' class D monitors tend to idle at at a mere couple of watts or so (eg Kali IN-5 even with three amps).

Could it lead to shorter lifespan of the electronics? (bearing in mind that they only have a two year warranty). Not to mention it being unwelcome in hot living spaces during summer.
 
Last edited:

IamJF

Senior Member
Joined
Apr 27, 2023
Messages
453
Likes
564
Location
Austria
My KH120ii run warm but not hot. As they have the same electronics ... I would wait for the 2nd one and compare.
These monitors run in bigger studios 24/7 and need to stay up for many years - or Neumann will not sell any of them any more. I don't think they do planned obsolescence as you imply here.
 

Curvature

Major Contributor
Joined
May 20, 2022
Messages
1,055
Likes
1,300
What's "warm"? What's "hot"? Measure the temperature and report it here and to Neumann for guidance.

Speakers don't only get hot because of the amps. They handle immense sound pressure internally.
 

Filio45

Active Member
Joined
Feb 19, 2019
Messages
162
Likes
74
These monitors run in bigger studios 24/7 and need to stay up for many years - or Neumann will not sell any of them any more. I don't think they do planned obsolescence as you imply here
Good point, other than the planned obsolecence part, which I wasn't implying at all.
 

Elder

Member
Joined
Mar 30, 2023
Messages
71
Likes
91
So they don't just run warm but 'hot'.

The SOS review of the KH 150 said that they used 'a patent-pending amp tech that combines superior audio performance with the energy efficiency of class D. The amp topography incorporates some novel techniques that take driver impedance into account with the feedback strategy..."

Neumann state 15w idle for the KH150 and, in comparison, many 'regular' class D monitors tend to idle at at a mere couple of watts or so (eg Kali IN-5 even with three amps).

Could it lead to shorter lifespan of the electronics? (bearing in mind that they only have a two year warranty). Not to mention it being unwelcome in hot living spaces during summer.

Heat can always be a factor in the lifespan of electronics, but I'm guessing Neumann designed the cooling to be sufficient to keep the amplifiers transistors well within their safe operating range.

If the heatsink is getting hot, that at least means there's a good interface between the amps components and the heatsink and that the heatsink is doing its job. Think I remember reading somewhere also that as a passively cooled heatsink heats up, it becomes more efficient at transferring the heat to the surrounding air. Could be wrong though.
 

IamJF

Senior Member
Joined
Apr 27, 2023
Messages
453
Likes
564
Location
Austria
Think I remember reading somewhere also that as a passively cooled heatsink heats up, it becomes more efficient at transferring the heat to the surrounding air. Could be wrong though.
A higher temperature difference transports more energy into the air.
You have an exponential cooling curve for tea cause of this. (-> always wait with adding your milk, let it cool first with the big temp difference)
 

Elder

Member
Joined
Mar 30, 2023
Messages
71
Likes
91
Not Class D but similar

I was wrong sorry, the following is the wording used by Neumann in their marketing material.

"Neumann engineers took great care to develop a patent pending amplifier technology which combines superior audio performance with the energy efficiency of Class D."
 

unpluggged

Senior Member
Joined
Jan 5, 2023
Messages
469
Likes
688
I was wrong sorry, the following is the wording used by Neumann in their marketing material.
It doesn't say it's not class D.
 

boxerfan88

Senior Member
Joined
Oct 23, 2018
Messages
318
Likes
366
If it’s not class-D, possibly class-H then?
 

Karmacoma

Member
Forum Donor
Joined
Nov 28, 2022
Messages
99
Likes
116
Location
France
I have some questions for the owners of these speakers or for people who understand measurements better than i do, how loud would they go in a 20m2/215sq feet room? (i saw the SPL measurements but I'm struggling to put them in perspective since i have no SPL-meter)
Also does their dsp solution automatically select a crossover (and whatever else) if you add a kh750 in the system to relieve the 6,5" driver, or do you have to select some of the parameters by yourself? Is it reasonably easy to manage? To summarise I'm not very educated on these matters and i'd like to understand if this could be the perfect system for me, a casual audiophile with no experience in dealing with dsp.
thank you for your attention
 

teashea

Addicted to Fun and Learning
Joined
Dec 23, 2022
Messages
689
Likes
761
Location
Nebraska
I have some questions for the owners of these speakers or for people who understand measurements better than i do, how loud would they go in a 20m2/215sq feet room? (i saw the SPL measurements but I'm struggling to put them in perspective since i have no SPL-meter)
Also does their dsp solution automatically select a crossover (and whatever else) if you add a kh750 in the system to relieve the 6,5" driver, or do you have to select some of the parameters by yourself? Is it reasonably easy to manage? To summarise I'm not very educated on these matters and i'd like to understand if this could be the perfect system for me, a casual audiophile with no experience in dealing with dsp.
thank you for your attention
The KH 150's are designed as nearfiled monitors. Look at the Neumann website and what they recommend. What you suggest is a very bad idea and misuse of these monitors. I use mine at 1.2 meters distance at most. From 2 meters they are still fine.
 
Top Bottom